Process of making waterproof rigid articles from pulp



May 22, 1923. 1,456,379

w. H. DRAKE ET AL PROCESS OF MAKING WATERPROOF RIGID ARTICLES FROM PULP Filed Feb. 2, 1920 wal ter H. Drake JamesJ. Drake Patented May 22, 1923.

warren sTA'rss Fries PATENT WALTER HENRY DRAKE AND JAMES JOSEPH DRA.KE, OF CLEVELAND, OHIO.

PROCESS OF MAKING WATERPROOF RIGID ARTICLES FROM PULP.

Application filed February 2, 1920. "Serial No. 355,827.

terproof Rigid Articles from Pulp, of which the following is a specification.

This invention relates to the process of making water proof rigid articles from pulp and has for an object to produce such articles by depositing upon the walls of a foraminous mold, pulp, the fibers of which are treated with a binder, which when heated,

fuse and form an intimate mass, and when cooled, become rigid and impervious.

The drawings illustrate conventionally an apparatus in which the process may be carried out, it being understood that such drawing is shown only for the purpose of illustrating the steps of the process and in no way effect the process as such. Such drawings show at Figure 1, a vertical diametrical sectional view with the mold closed and Figure 2, shows a vertical diametrical sectional view with the mold open to discharge the completed article.

In the carrying out of the present process, the pulp is prepared in any usual and ordinary manner, as it might be prepared for paper making or the like and at any step of the process, but preferably in the beater, the pulp is treated with a material which later will produce the water proofing and rigidifying binder. The material so added is the usual and ordinary sizing material consisting in first emulsifying the pulp by the ad dition thereto, of rosin soap, known as paper makers soap, and after the formation of such emulsion, adding thereto alum, which reacts with the emulsified rosin to produce an aluminum resinate, which is precipitated as a coating upon each and every individual fiber of the pulp. The pulp so treated with the aluminum resinate is conducted to the receptacle 10, as shown in the drawings. From the receptacle 10, a conduit 12 dedepends, controlled by a valve 14:,and with a valved pipe lfi introduced below the valve 14. To the conduit member 12 the mold vsections 16 and 17 are hinged, so that they may be closed together as shown at Figure 1 in position to receive the inflowing pulp, or may be separated as shown at Figure 2, for the purpose of discharging the completed article. As shown in the drawing theshape of the foraminous mold indicates the production of a milk bottle, but it is to be understood that such form, shape and proportion are in no way limiting upon the invention and that the invention includes the production of containers of other shapes, sizes and proportions and articles other than containers.

From the conduit 12, a duct 18, depends preferably coinciding with the axis of the mold and extending nearly to the bottom thereof. A telescoping section 19 is preferably formed upon the end of the duct 18, for the purpose of regulating the oint of discharge of the pulp within the mo (1. The

discharge of the pulp in this manner and the I deposition of the pulp upon the walls of the foraminous mold, is not novel in the present application, being the subject matter of Patent No. 1,305,203, issued May The pulp carrying the aluminum resinate is discharged into the mold and by reason of the position of the duct and the force of the inflow of pulp, the pulp is moved upwardly along the walls of the mold and de- %sited in a uniform layer upon such walls.

hen a suflicient amount of the pulp has been deposited to produce the desired thickness of article, the valve 14 is closed to cut off further inflow. Heated air is now admitted through the pipe 15 into the mold, expelling the remainder of the fiuid carriage. The air, or if desired, super-heated steam, so employed, is of such temperature as to fuse or melt the aluminum resinate carried by the fibers. The exact temperature of melting or fusing of this aluminum resinate is not known at the resent time, but is probably somewhere a out 400 degrees F. Aluminum resinate is rigid at a temperature well above the temperature of boiling water, after passing which point it becomes softened and plastic and when the temperature has been raised to a sufficient degree, becomes fluid. The heat necessary to completely melt or fuse the aluminum resinate, quickly dries the moisture from the pulp, so that it performs the double function of drying the arti cle and fusing the aluminum resinate. It appears that the forcing of the heated air through the pulp does not tend to displace the aluminum resinate coating the individual fibers, but only melts'such coating to such an extent that as soon as the heated ai is interrupted by closing the valve in the pipe 15, the contiguous'fibers adhere by the aluminum resinate beEoming substantially a homogeneous mass, rigidifying with v the drop of temperature. The use .of aluminum resinate as a sizing for paper has never contemplated the fusing thereof, as such fusing and subsequent cooling renders the article rigid which is a condition undesired for paper and inoperative for water proof ing for the reason that bending and folding fractures the water roofin substance. For an article wherein r1 idity 1s a desideratum, the fusing and rigidifying of the binder, adds not only the desired water proofing,

vbut also greatly to the rigidity of the article.

Takinga container as an example, the aluminum resinate remains rigid well above the temperture of boiling water, so that a container water proofed with this material, is impervious, not only to cold water, but also to boiling water.

Furthermore, the high temperature to which the article is subjected for the purpose of fusing the aluminum resinate, completely antisepticizes the material, so that the article discharged from the mold is not only completely water proofed, but is rigid and aseptic.

While alum has been specified as the reagent for actin upon the resinous emulsion, it is undoubte ly true that other reagents may be similarly employed in which case the precipitate would naturally not be aluminum resinate, the exact formula depending upon the reagent employed and Where aluminum resinate has been mentioned in this specification, or the claims, it is to be understood that any e uivalent resinate is comprehended within t e term.

While the drawing would indicate that the intent of this invention is the making of hollow articles that may be made in a separable mold, it is to be understood that it is not so limited and that it comprehends the making of any article of whatever shape as for instance composite board or the article of commerce ordinarily known as wall board or any article for any purpose where a rigid waterproof pulp article would be desirable.

W e claim 1. The process of waterroofing an article composed of fiber, conslsting in' coating aaeaaro the fibers with aluminum resinate, depositing the coated fibers in the required form and forcin through the fibrous mass a flui heated to t e temperature of melting of the aluminum resinate.

2. The process of water-proofing an article composed of pulp, consisting in treating the pulp with materials to precipitate aluminum resinate upon the fibers, depositing the coated fibers upon a surface having the required contour, and subjecting the fibrous deposit to a heat sufiicient to melt and fuse the'aluminum resinate while still in contact with the contoured surface.

3. The process of water-proofing and rigidifyingan article composed of pulp, consisting in depositing the fibers of the pulp upon a surface having the required contour and depositing therewith a bin er material adapted to be fused and melte -by the applicatlon of heat thereto and to become rlgid at a temperature above the temperature of boiling water.

4:. The process of water-proofing an article composed of pulp, consisting in depositin the fibers of p111 upon a contoured sur ace commingled Wit a resinous material capable of being fused and melted by the application of heat thereto and to become rigid at a temperature above the temperature of boiling water, and applying a sufiicient degree of heat to the pulp while in contact with the contoured surface to fuse and melt the binder.

5. The process of water-proofing an article composed of pulp, consisting in employing a foraminous mold introducing the pulp under pressure to the foraminous mold, to deposit the pulp fibers and discharge the carriage, commingling with the pulp fibers so deposited a binding material capable of melting by the application of heat and to become rigid at a temperature above the temperature of boiling water and subjecting the article to heat whilecontained within the mold.

6. The process of water-proofing an article composed of pulp, consisting in commingling with the pulp an aluminum resinate, depositing the commingled pulp fibers and aluminum resinate upon a foraminous surface, and forcing through the pulp deposit and foraminous surface, a fluid heated to a temperature to melt and fuse the alumi-' num resinate.

7. The process of waterproofing an article composed of pulp consisting in commingling with the pulp fibers a resinous binder, de-

positing the commingled materials upon a contouring surface, removing the aqueous carriage and fusing the binder while yet in contact with the contouring surface.

8. The process of waterproofing an article composed of pulp consisting in emulsifying the pulp with a. resinous saponifier, pre- In witness whereof, we have hereunto set cipitating the resins on to the pulp fibers our hands and seals at Cleveland, Cuyahoga in the form of aluminum resinate by the County Ohio this 31st day of January, A. 10 addition of alum to the emulsion, contouring D., nineteen hundred and twenty.

5 the pulp and driving off the carriage by forcing therethrough anh drous fluid at a WALTER HENRY DRAKE. [1,. 5.] temperature to fuse the a uminum resinate. JAMES JOSEPH DRAKE. [1,. s.] 

